1. Field of the Invention
The present invention relates to a coupling device and more particularly to such a coupling device which is operable conveniently, efficiently and securely to connect a vehicle to be towed with a towing vehicle while simultaneously elevating a pair of wheels of the vehicle to be towed from ground engagement without the use of any auxiliary lifting equipment or assistance.
2. Description of the Prior Art
Characterizing the closest prior art of which the applicant is aware and in compliance with 37 C.F.R. 1.97 and 1.98, attention is invited to the following patents, copies of which are attached:
U.S. Pat. No. 1,851,349, Cowles; Mar. 29, 1932 PA1 U.S. Pat. No. 2,628,733, Hale; Feb. 17, 1953 PA1 U.S. Pat. No. 3,758,135, Kniff; Sept. 11, 1973 PA1 U.S. Pat. No. 3,885,815, Kniff; May 27, 1975 PA1 U.S. Pat. No. 3,984,120, Boveia; Oct. 5, 1976
The Cowles U.S. Pat. No. 1,851,349 discloses a vehicle coupling operable to interconnect a vehicle to be towed and a towing vehicle through movement of the vehicles relative to each other. The coupling utilizes a slidable draft bar and rollers.
The Hale U.S. Pat. No. 2,628,733 relates to a towing dolly which employs a winch in combination with a trailer having a pivotal bed to elevate a pair of ground engaging wheels of a vehicle to be towed.
The Kniff U.S. Pat. No. 3,758,135 is directed to an automobile tow bar operable for use in towing a vehicle with a pair of ground engaging wheels elevated from such ground engagement.
The Kniff U.S. Pat. No. 3,885,815 discloses a towing device operable for towing a vehicle with the rear wheels thereof out of ground engagement.
The Boveia U.S. Pat. No. 3,984,120 reveals an auto towing apparatus incorporating a hoist assembly in combination with a frame for elevating a pair of wheels of an automobile to be towed from ground engagement.
The difficulties associated with the towing of one vehicle by another are many. Of course, the primary objective is simply to establish interconnection of the two vehicles. However, the vehicle to be towed is often smaller and lower to the ground than the towing vehicle which can interfere with linking of the two vehicles. Although commercial towing vehicles employ various mechanisms for establishing interconnection in such cases, these mechanisms are frequently quite expensive and impractical for use in non-commercial evironments. Normally the only facility available for use on a towing vehicle in non-commercial situations is a conventional ball hitch.
Another impediment is that most vehicles require either the front or rear wheels thereof to be lifted out of ground engagement for towing if damage is to be avoided. The problem resides in the fact that lubricating oil is not supplied to portions of certain vehicles, such as the transmission, when the engine is not in operation. In many vehicles towing causes these portions to be operated and serious damage may be the result. Accordingly, in order to avoid such damage it has heretofore been necessary to use a winch of some type to raise the front or rear of the vehicle, as recommended, out of ground engagement and then to interconnect the vehicles for towing. In other cases, jacks are used to elevate the appropriate portion of the vehicle. In any event, these operations often require the attention of two or more persons working in cooperation for a lengthy period of time and under rather dangerous conditions to achieve the desired result.
Therefore, it has long been known that it would be desirable to have a coupling device which could rapidly be operated by a single individual conveniently, effectively and safely to interconnect a pair of vehicles while simultaneously raising a pair of wheels of one of the vehicles out of ground engagement for towing without risk of damage to either vehicle.